Sizing a write cache buffer based on emergency data save parameters

Abstract

Embodiments relate to saving data upon loss of power. An aspect includes sizing a write cache buffer based on parameters related to carrying out this emergency data save procedure. A computer implemented method for allocating a write cache on a storage controller includes retrieving, at run-time by a processor, one or more operating parameters of a component used in a power-loss save of the write cache. The component is selected from the group consisting of an energy storage element, a non-volatile memory, and a transfer logic. A size for the write cache on the storage controller is determined, based on the one or more operating parameters. A write cache, of the determined size, is allocated from a volatile memory coupled to the storage controller.

What is claimed is: 
     
       1. A computer implemented method for allocating a write cache on a storage controller, the method comprising:
 retrieving, at run-time by a processor of a storage controller, one or more operating parameters of a transfer logic residing on an application specific circuit (ASIC), the one or more operating parameters including an instance-specific process speed of the transfer logic, wherein
 the instance-specific process speed is retrieved as bin data, 
 the transfer logic is configured to copy, upon power loss, contents of a write cache in a volatile memory to a non-volatile storage, and 
 the storage controller includes the volatile memory, the non-volatile storage, the ASIC, the instruction memory, and the processor; 
 
 determining a voltage of the transfer logic based on the instance-specific process speed of the transfer logic; 
 calculating an energy consumption rate of the transfer logic during the copy upon power loss, wherein the calculating is based on the voltage, a current temperature of the transfer logic and the one or more operating parameters that are obtained at run-time; 
 determining a size for the write cache in the volatile memory, based on the energy consumption rate and an amount of energy in an energy storage element that powers the power-loss save; and 
 allocating the write cache, of the determined size, from the volatile memory.